Clamping-finger.



UNITED STATES PATENT OFFICE.

WILLIAM L. R. EMMET, OF SCHENECTADY, NEV YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CLAMPING-FINGER.

SPECIFICATION forming part of Letters Patent No. 714,881, dated December 2, 1902- Application tiled May '7, 1902. Serial No. 106.323. (No model.)

To all wiz/0m t may concern:

Be it known that I, WILLIAM L. R. EMMET, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Clamping-Fingers, (Case No. 2,4430 of which the following is a specilication.

This invention relates to the laminated cores of dynamo-electric machines; and its object is to provide an improved end-clamping linger for the same. As is well known, these cores are made of a plurality of varnished sheetiron laminations placed side by side and clamped tightly together, with Ventilatingspaces at suitable intervals. Each lamination is a ring or a segment of a ring having slots cut in one edge to receive the coils. The teeth between the slots are usually rather narrow and being made of thin sheet metal they must be firmly clamped to prevent them from displacement. It is therefore necessary in machines of this class to provide a rigid iinger running out along each tooth to impart a heavy pressure thereto when the core is clamped together. The ends of the fingers are usually curved inward somewhat to insure an extra pressure at the tip of the tooth. These clamping-fingers are usually made of brass or cast-iron, several such being cast integral with ,connecting-bars and forming a segment of a circle corresponding with the diameter of the held-magnet or armature on which it is to be used. These segments are clamped against the ends of the core by through-bolts or by heavy plates of cast-iron fastened by screws to the frame carrying the core. Sometimes the finger is made of a strip of stiff sheet-steel placed edgewise against the tooth and riveted to a heavy ring or segment of sheet-iron. The cast fingers are usually applicable to only one size of machine, so that a separate pattern is necessary for each size. The narrow sheet-steel fingers do not well support the teeth, as they lie only along the middle thereof. Moreover, having only a narrow bearing, they are liable to buckle under heavy clamping pressure.

'My invention aims to provide a finger which is applicable to manysizes of machines and has a broad bearing on the tooth, so that it gives vreceive a heavier pressure.

good support to said tooth over a large part of its surface. My finger is, moreover, light in weight, contains a minimum of material, and is so designed that one pattern will be applicable to cores in which the length of the teeth and the depth of body portions vary considerably. By keeping in stock only three or four patterns of finger I ain able to build almost any size of machine by simply cutting off the surplus material from one end of the iinger to fit it to the smaller sizes.

The finger I have invented is made of sheet metal, preferably steel, pressed up into a trough-shaped bar, preferably U-shaped in cross-section and tapering down to a rounded tip at one end. This end is also curved somewhat, so that when the trough is held horizontally, open side up, its edge has an upward sheer at the closed end. The linger has lugs on its edges by which it can be riveted to an end lamination of heavy sheet metal.

In the accompanying drawings, Figure 1 is an end view of a portion of the field-magnet and armature-cores of a dynamo-electric machine provided with my improved clampingiingers. Fig. 2 is a perspective view of one of said lingers. Fig. 3 is a cross-section of the field-magnet and armature-cores, showing the clamping-lingers at each end. Fig. 4 illustrates the application of one size of finger to laminations having different depths of tooth and body. l

Referring to Fig. 2, it appears that the finger l is a trough-shaped structure having one end 2 open and the other end tapered down to a closed rounded tip 3, whose edges are curved upward somewhat out of the line of the parallel edges 4 of the remainder of the finger. Not far from the tip are two or more lugs 5, projecting from each edge 4E. When the linger is laid radially on an end lamination 6, with the tip extending out to the end of the tooth 7, these lugs 5 pass through slots punched in the body of the lamination and are riveted down on the inside thereof to secure the linger in place. The curved tip bends the tooth a little to one side, so that when thegend lamination is laid in place and thecoreis clamped up the ends of the teeth The lugs 5 are "so located that the linger will be applicable IOO to a lamination having a long tooth 8 and a deep body portion 9 or to a lamination having a short tooth 10 and a narrow body 11, the slots 12 being properly located to receive the lugs in both cases. For a narrow body the finger willbe cut off at the line x, Fig. 4.

The nger is Wide enough to cover a considerable Width of the tooth, and thus give it a firm support. It is light and stiff and contains but a small amount of metal, Well disposed to resist the strains to which it is subjected. Two or three Widths and lengths of inger Will be lsulicient for building all commercial sizes of machines.

What I claim as new, and desire to secure by Letters Patent of the United States, is

l. An end-clamping linger for laminated cores of dynamo-electric machines, consisting of a trough-shaped structure of sheet metal.

2. .An end-clamping linger for laminated cores of dynamo-electric machines, consisting of a trough-shaped structure of sheet metal closed at one end.

3. An endclamping finger for laminated cores of dynamo-electric machines, consisting of a trough-shaped structure of sheet metal having lugs along its edges.

4. An end-clamping finger for laminated cores of dynamo-electric machines, consisting of a trough-shaped Ystructure of sheet metal having a rounded tip at one end.

5. An end-clamping finger for laminated cores of dynamo-electric machines, consisting of a trough-shaped structure of sheet metal having a closed rounded tip at one end curved slightly inward.

(3. An end-clamping finger for laminated cores of dynamo-electric machines, made of sheet metal and having a broad bearing'on the core lamination.

7. YThe combination of a lamina for dynamoelectric machines, and a clamping finger or fingers riveted thereto.

8. The combination of alamina for dynamoelectric machines,and atrough-shaped clamping finger or fingers fixed thereupon.

9. The combination of alaminafor dynamoelectric machines provided with apertures, and a pressed-m etal clamping fmger or n gers having lugsV or projections engaging said apertures.

In Witness whereof I have hereunto set my hand this 5th day of May, 1902.

VILLIAM L. R. EMMET.

Witnesses:

BENJAMIN B. HULL, HELEN ORFoRD. 

